This invention relates to an energy saving device for a two-lamp rapid-start series-sequence fluorescent lamp system.
In recent years there have been a number of devices disclosed for reducing the power consumed by existing fluorescent lamp systems. In U.S. Pat. No. 3,954,316, dated May 4, 1976, issued to J. F. Leuchetta, is described an attachment for inclusion in a two-lamp rapid-start type fluorescent lamp. It comprises an isolation transformer and a capacitor to reduce the electrical power consumption of the lamp. The capacitor is placed in series with the existing power factor correcting capacitor in the standard ballast and thereby reduces current after energization. The isolation transformer provides heater current for one of the electrodes of one of the lamps and also functions to improve the power factor.
In U.S. Pat. No. 3,956,665, dated May 11, 1976, issued to J. A. Westphal, is disclosed an energy saving device for replacing a fluorescent lamp in a two-lamp serially connected fluorescent fixture. Frequently, in order to save energy, every other set of two fluorescent lamps are disconnected with their ballasts remaining in the circuit. The unloaded ballasts have an undesirable inductive power factor. The Westphal device permits the use of one of the two lamps by placing a capacitor in series with the lamp, thereby providing somewhat improved light distribution and power factor.
The present invention is an improvement over the prior art in that it is relatively inexpensive, readily adaptable to existing fluorescent lamp systems, and provides good light distribution and power factor.